The Biodefense Training Program is designed to prepare doctoral students for careers in a variety of research disciplines critical to protecting the US and other parts of the world from bioweapons and naturally emerging, highly pathogenic bacteria and viruses. The University of Texas Medical Branch is well qualified to provide this training by virtue of its state-of-the-art high containment facilities, major biodefense research programs, and outstanding faculty who study most of the major bioweapons. The research topics within the University of Texas Medical Branch biodefense portfolio are also unusually diverse, ranging from vaccine development to diagnostics to antimicrobial development to pathogenesis, and the programs are highly collaborative and interdisciplinary. The training program will focus on PhD students who are enrolled in three graduate programs: experimental pathology, microbiology and immunology, and biochemistry and molecular biology. Trainees will be selected by a committee after completion of the qualifying exam and will be supported for one to two years during their dissertation research. Fifteen senior, highly experienced faculty mentors will participate in the program, along with an additional 18 associate program faculty including both persons who provide specialized expertise and training, and junior faculty who will be eligible to mentor students with a Primary Faculty co-mentor. This latter arrangement is designed to develop junior faculty into effective graduate student mentors under the tutelage of experienced and accomplished senior faculty. Support for four trainees is requested.